Accidentally Sent BTC from Electrum to Coinpayments.net Wallet (unconfirmed)

[Bobalooga]

This was two days ago. I paid the vendor for my product in LTC (litecoin) AFTER I first sent out a BTC payment that is still unconfirmed (says Replaceable because the fee is too low right now obviously) . LTC is just so much faster and cheaper and I didn't think quick enough.

What's the cheapest (or free?) way to reverse this so the BTC
just stay in the Electrum account and never go to the Coinpayments.com BTC wallet?

Thanks,
Bobalooga